Re: Re: [COMMITTERS] pgsql: Avoid extra locks in GetSnapshotData if old_snapshot_threshold <

On 2016-05-02 09:03:19 -0400, Robert Haas wrote:
> On Fri, Apr 29, 2016 at 6:08 PM, Kevin Grittner <kgrittn@gmail.com> wrote:
> > Now to continue with the performance benchmarks.  I'm pretty sure
> > we've fixed the problems when the feature is disabled
> > (old_snapshot_threshold = -1), and there are several suggestions
> > for improving performance while it is on that need to be compared
> > and benchmarked.
> 
> If anyone thinks that the issue with the feature disabled is NOT
> fixed, please speak up!  I'm moving the corresponding open item to
> CLOSE_WAIT status, meaning that it will be closed if nobody shows up
> to say that there is still an issue.

Well, I don't agree that the feature is in a releaseable state. The
datastructure is pretty much non-scalable, and maintained on the wrong
side (every read, instead of once in writing writing xacts). There's no
proposal actually addressing the scalability issues.

Andres